Preparation method of bis(fluorosulfonyl)imide salt

The invention relates to the field of chemical synthesis of fluorine-coritaining materials, particularly a preparation method of bis(fluorosulfonyl)imide salt. The preparation method comprises the following step: carrying out replacement reaction on bis(fluorosulfonyl)imide, an alkali metal fluoride MF and silicon tetrahalide in the presence of a solvent to obtain the bis(fluorosulfonyl)imide salt. The preparation method provided by the invention avoids using abundant water in the production process, thereby relieving the environmental protection pressure, and avoiding the decomposition quality decrease of the product due to the introduction of water. Thus, the preparation method is more suitable for industrial production.